diff --git a/CHANGELOG.md b/CHANGELOG.md
index 491f224..3de75fa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -53,6 +53,7 @@ To have a consistent experience across all packages, some public interfaces have
 - **request.result:** Fold `IsSuccess` into `Result<T>.GetHashCode` to avoid collisions between a failure and a success value whose hash is `0`
 - **request.validation:** Guard null comparison bounds in `GreaterThan`/`LessThan`/`Between` etc. so a `null` bound no longer throws (`NullReferenceException`)
 - **request.validation:** Return no problems when validating a `null` instance of a reference type instead of dereferencing it (`NullReferenceException`)
+- **request.validation:** Make `Severity` meaningful — `Validation.IsValid` now only fails on `Error` problems; `Warning`/`Info` no longer invalidate. Added `Validation.IsValidFor(Severity)` to set the failing-severity threshold (see PLAN.md Inconsistencies#B)
 
 ### Removed
 
diff --git a/src/request.validation.tests/ValidationSeverityTests.cs b/src/request.validation.tests/ValidationSeverityTests.cs
new file mode 100644
index 0000000..6f24c8d
--- /dev/null
+++ b/src/request.validation.tests/ValidationSeverityTests.cs
@@ -0,0 +1,49 @@
+// Copyright (c) The Geekeey Authors
+// SPDX-License-Identifier: EUPL-1.2
+
+namespace Geekeey.Request.Validation.Tests;
+
+internal sealed class ValidationSeverityTests
+{
+	[Test]
+	public async Task I_can_have_warning_problems_not_invalidate_by_default()
+	{
+		var validator = new PropertyValidator<Person, string?>(person
+			=> person.Name, rule => rule.Must(value => !string.IsNullOrWhiteSpace(value), "Name is required.")
+			.WithSeverity(Severity.Warning));
+
+		var result = validator.Validate(new Person { Name = "" });
+
+		await Assert.That(result.Problems).Count().IsEqualTo(1);
+		await Assert.That(result.IsValid).IsTrue();
+		await Assert.That(result.IsValidFor(Severity.Warning)).IsFalse();
+		await Assert.That(result.IsValidFor(Severity.Info)).IsFalse();
+	}
+
+	[Test]
+	public async Task I_can_have_info_problems_only_invalidate_at_info_threshold()
+	{
+		var validator = new PropertyValidator<Person, string?>(person
+			=> person.Name, rule => rule.Must(value => !string.IsNullOrWhiteSpace(value), "Name is required.")
+			.WithSeverity(Severity.Info));
+
+		var result = validator.Validate(new Person { Name = "" });
+
+		await Assert.That(result.Problems).Count().IsEqualTo(1);
+		await Assert.That(result.IsValid).IsTrue();
+		await Assert.That(result.IsValidFor(Severity.Warning)).IsTrue();
+		await Assert.That(result.IsValidFor(Severity.Info)).IsFalse();
+	}
+
+	[Test]
+	public async Task I_can_have_error_problems_invalidate_by_default()
+	{
+		var validator = new PropertyValidator<Person, string?>(person
+			=> person.Name, rule => rule.Must(value => !string.IsNullOrWhiteSpace(value), "Name is required."));
+
+		var result = validator.Validate(new Person { Name = "" });
+
+		await Assert.That(result.IsValid).IsFalse();
+		await Assert.That(result.IsValidFor(Severity.Error)).IsFalse();
+	}
+}
diff --git a/src/request.validation.tests/ValidatorTests.cs b/src/request.validation.tests/ValidatorTests.cs
index 6613720..820edc4 100644
--- a/src/request.validation.tests/ValidatorTests.cs
+++ b/src/request.validation.tests/ValidatorTests.cs
@@ -14,7 +14,8 @@ internal sealed class ValidatorTests
 
 		var result = validator.Validate(new Person { Name = "" });
 
-		await Assert.That(result.IsValid).IsFalse();
+		await Assert.That(result.IsValid).IsTrue();
+		await Assert.That(result.IsValidFor(Severity.Warning)).IsFalse();
 		await Assert.That(result.Problems).Count().IsEqualTo(1);
 
 		var problem = result.Problems.Single();
@@ -39,7 +40,8 @@ internal sealed class ValidatorTests
 
 		using (Assert.Multiple())
 		{
-			await Assert.That(invalid.IsValid).IsFalse();
+			await Assert.That(invalid.IsValid).IsTrue();
+			await Assert.That(invalid.IsValidFor(Severity.Warning)).IsFalse();
 			await Assert.That(valid.IsValid).IsTrue();
 			await Assert.That(valid.Problems).IsEmpty();
 		}
diff --git a/src/request.validation/Validation.cs b/src/request.validation/Validation.cs
index fadadff..8e9c7c7 100644
--- a/src/request.validation/Validation.cs
+++ b/src/request.validation/Validation.cs
@@ -23,7 +23,27 @@ public sealed class Validation
 	/// <summary>
 	/// Whether the validation was successful.
 	/// </summary>
-	public bool IsValid => Problems.Count is 0;
+	/// <remarks>
+	/// A validation is considered successful unless it contains at least one problem with
+	/// <see cref="Severity.Error"/>. Problems of lower severity (<see cref="Severity.Warning"/> or
+	/// <see cref="Severity.Info"/>) do not invalidate the result. Use <see cref="IsValidFor"/>
+	/// to control which severities are treated as failures.
+	/// </remarks>
+	public bool IsValid => IsValidFor(Severity.Error);
+
+	/// <summary>
+	/// Whether the validation was successful, treating problems at or above the given severity as failures.
+	/// </summary>
+	/// <param name="minimum">The minimum severity that should be considered a failure.</param>
+	/// <remarks>
+	/// A problem invalidates the validation when its <see cref="Severity"/> is at least as severe as
+	/// <paramref name="minimum"/>. For example, <c>IsValidFor(Severity.Warning)</c> fails on errors and
+	/// warnings but not on informational problems.
+	/// </remarks>
+	public bool IsValidFor(Severity minimum)
+	{
+		return !Problems.Any(problem => problem.Severity <= minimum);
+	}
 
 	/// <summary>
 	/// The problems that were found during validation.